The invention concerns a telescopic boom and more particularly relates to a routing assembly for transmission lines contained in the boom.
On telescopic booms of vehicles, particularly on telescoping loaders and the like, transmission lines are frequently routed that are used to transmit hydraulic, electrical and/or pneumatic power and/or to transmit signals, in order to drive, for example, hydraulic or pneumatic cylinders, valves and electric motors or to accept inputs of measurement values. In order to make possible an equalization of the lengths of the transmission lines upon the retracting and extending of two telescoping sections of the boom, it is usual practice (EP-B-0 623 092, U.S. Pat. No. 3,623,501) to employ flexible transmission lines that are conducted in a wide arc, each of whose ends is fastened to one of the two telescoping sections that can be moved relative to each other. The direction and routing of these transmission lines, however, is frequently difficult. Since the transmission lines are usually conducted in bundles, maintenance operations or the replacement of the lines are difficult to perform.
From U.S. Pat. No. 3,985,248, a telescopic boom arrangement has become known in which two flexible line sections extending in the form of a loop are fastened at one end to an outer boom section and at the other end to an inner boom section. Each loop is conducted in the opposite direction over an associated pulley. The two pulleys are supported in bearings on a slide guided on a guide rod. During extension and retraction of the boom, the slide shifts and thereby an equalization of the length of the line sections takes place. This configuration is relatively costly and requires a large amount of justification and maintenance.
According to the present invention, there is provided a routing arrangement for transmission lines which overcomes the problems attendant with the routing arrangements of the prior art.
An object of the invention is to provide a simple, economical assembly for reliably routing transmission lines used with a telescopic boom.
A more specific object is to provide a transmission line mounting frame to which is fixed a first transmission line receptacle holding first ends of transmission lines and a guide assembly on which a second receptacle, in the form of a slide and holding second ends of the transmission lines, is mounted for reciprocating along the guide assembly, with a flexible bow being located in the transmission lines between the first and second receptacles.
Yet a more specific object is to provide a mounting frame, as defined in the immediately previous object, wherein a plate extends longitudinally of the mounting frame for supporting and guiding the bow portion of the transmission lines.
Still another specific object is to provide a transmission line routing assembly as defined in one or more of the previous objects, wherein the transmission lines extending between the first and second receptacles are an intermediate section having opposite ends adapted for connection to further transmission line sections respectively carried by the boom vehicle and by a telescoping boom section.